Study of the differences in soil properties between the dry season and rainy season in the Mun River Basin

摘要

The Mun River Basin is the main grain-producing area of northeastern Thailand. Natural factors in this area have led to significant dry and rainy seasons, which, coupled with human influences, have further resulted in spatial and temporal differences in soil conditions, leading to low agricultural productivity. Therefore, an analysis of the soil conditions in the dry season and in the rainy season in the Mun River Basin is necessary for soil remediation and improvement, which will be good for regional agricultural development. This study used soil samples in the dry season and rainy season to determine the differences in indicators and soil quality at temporal and spatial scales in the Mun River Basin. The minimum dataset theory was used to screen evaluation indicators, a geographically weighted regression was selected to finish the spatial interpolations of soil indicators, and a fuzzy logic model was used to evaluate the soil quality. The results showed that the spatial distributions of different indicators and soil quality were similar, with the soil contents and quality decreasing from the west to east of the basin. However, the contents of soil organic matter and available phosphorus decreased, while total nitrogen increased at different times, and approximately 58% of the basin had an increase in the soil quality from the dry season to the rainy season. The overall soil condition of the basin was poor, and the soil quality in the rainy season was more uniform than that in the dry season. The soil quality in forests and dry fields was higher than in other land use types, while the soil conditions in most paddy fields were not ideal. In general, the results were helpful for soil improvement and for increasing the grain production in the Mun River Basin.